离子束辐照的碳纳米管及其物性研究

离子束辐照通常被认为导致材料产生缺陷, 形成无序结构, 从而破坏材料的性能。 但是, 最近利用离子束辐照碳纳米管的实验显示离子束辐照碳纳米管形成无定形的过程不能用传统的离子束辐照材料的机制来解释, 离子束辐照可导致碳纳米管形成一些自组装结构, 如无定形碳纳米结和碳纳米管连接结等。 研究还发现离子束辐照的碳纳米管薄膜在导电性和场发射性能方面都能得到明显的增强。 Ion beam irradiation is usually thought to induce defects and disordered structures in materials and then to destroy the properties of the materials. However, our recent experiments about the ion beam irradiation on carbon nanotubes(CNTs) indicate that the ion beam modification mechanism of CNTs is completely different from traditional one of bulk materials, and ion beam irradiation can lead to self organized structures in CNTs, such as amorphous junctions and CNT junctions. Moreover, the irradiated CNTs exhibit a improved conductivity and an enhanced field emission.     

上海光源在材料与能源科学中的应用

<正>材料在日常生活中无处不在,一般包括金属、陶瓷、高分子材料(比如塑料)、半导体以及复合材料等,是人类赖以生存和发展的物质基础。材料往往由于其独特的微观结构,而导致外在宏观性能的大幅度提高。比如说,使电灯发光的钨丝、人类信     

基于4MV静电加速器的高温辐照装置研制及离子辐照初步实验北大核心CSCD

为了模拟钍基熔盐堆(TMSR)材料的中子辐照损伤,基于中国科学院上海应用物理研究所(SINAP)的4 MV静电加速器,研制了一台专用的离子束辐照装置。装置主要由束流传输线和高温、高真空靶室组成。束流传输线装有用于束流磁场扫描和束流监测的设备。装置可提供H^+,He^+,Ar^+等束流用于离子束辐照,束流最高能量4 Me V,最大流强2μA。辐照温度范围为液氮温度至950℃。辐照面积最大为30 mm×30mm。装在靶室的由旋转铝片构成的变能器对束流能量进行调制,可以在样品中得到均匀的辐照损伤。初步的实验结果表明,装置适用于高温合金及其他熔盐堆材料的辐照损伤研究。     

Strain Induced Metastable Phase and Phase Revolution in PbTiO3-CoFe204 Nanocomposite Film

An inter-component epitaxial strain-induced PbTiOa metastable phase is observed in a PbTiO3-GoFe2O4 epitaxial composite film, corresponding to the dielectric anomaly reported previously. High-resolution synchrotron radiation X-ray diffraction and first principles calculation demonstrate the coexistence of different PbTi03 phases, even a possible morphotropie phase boundary in the film, elucidating the underlying microscopic rneehanism of the formation of Pb TiO3 metastable phase. This sheds light on the design and manipulation of electromechanical properties of epitaxial films, through the strain engineering.